CN110622041A - Seismic node deployment system - Google Patents

Abstract

The seismic node deployment system includes a cable provider, wherein one or more seismic nodes are configured to be coupled to a cable at one or more attachment locations for deployment to a water column. The node attachment system is configured to drive a portion of the cable into a periodic or reciprocating motion such that the attachment speed is substantially reduced relative to the speed at which the cable is deployed.

Description

Seismic node deployment system

Cross Reference to Related Applications

The present application claims priority from U.S. provisional patent application No. 62/509,922 entitled "semiconductor node deployment system" filed on 23/5/2017, and U.S. provisional patent application No. 62/517,334 entitled "semiconductor node deployment system" filed on 9/6/2017, each of which is incorporated herein by reference in its entirety and for all purposes.

Technical Field

The present disclosure relates generally to seismic data acquisition, including but not limited to seismic node deployment for marine seismic surveys. The present disclosure also relates to a system or apparatus for attaching autonomous devices such as acoustic positioning systems or seismic nodes or other sensor nodes (collectively referred to as nodes) to ropes, cables or wires, for example for deployment into a water column or other seismic medium.

Background

Modern geophysical exploration techniques include land-based and marine seismic surveys. In marine surveying, a seismic research vessel typically tows a source, such as an air gun array, which periodically emits acoustic pulses generated by breaking up bubbles. Sound waves propagate through the water column and penetrate the sea bed or seafloor, where the sound waves are reflected from boundaries between subsurface overburden of the geological structure. The reflected acoustic energy is detected by an array of seismic sensors or receivers that generate seismic sensor data that can be processed to reconstruct the reflected wavefield and generate an image corresponding to the subsurface geology.

Typically, the seismic receivers are distributed along a series of tow cables (streamer lines) towed behind a seismic vessel, or deployed directly onto the seabed along a submarine cable. The receivers may also be deployed as an array of individual autonomous sensor nodes.

Within the water column, acoustic energy is primarily characterized by the propagation of pressure-type acoustic waves (P-waves). Thus, towed seismic streamer arrays have traditionally utilized pressure sensitive receivers, such as hydrophones. On the other hand, the subsurface wavefield includes both pressure and shear waves (S-waves) in addition to the more complex wavefield contributions. Modern ocean bottom seismic systems therefore employ motion sensitive devices such as geophones and accelerometers, for example, in sensor sub-arrays combining hydrophone and multi-axis geophone components, sensitive to both differential pressure and motion (velocity or acceleration) along three orthogonal axes.

In this more general approach, the pressure and shear wave contributions are combined to more accurately reproduce the complete seismic wavefield and generate a more complete image of the subsurface geology. Similar techniques may also be applied to land-based surveys, where both pressure and shear wave data are also available.

To accurately track and record the large amounts of seismic sensor data required to achieve these results, a sophisticated clock system is typically provided, along with local data processing and storage components, power supplies, and interfaces configured for control and data communications. As the data capacity of each of these components increases, there is an increasing demand for improved seismic imaging techniques suitable for processing correspondingly larger data streams.

The information included in the background section of the specification, including any references cited herein and any descriptions or discussions thereof, is included for technical reference purposes only and should not be taken as subject matter which limits the scope of the invention as defined in the claims.

Disclosure of Invention

The present disclosure relates to seismic data acquisition and seismic node deployment. The present invention encompasses system and method embodiments including, but not limited to, systems, methods and apparatus adapted to attach seismic nodes, receivers or other autonomous sensing devices, or alternatively acoustic transmitters or other repeaters (hereinafter collectively referred to as "nodes") for location identification or other information transmission, to ropes or cables or wires for deployment into a water column or other seismic medium. In the present disclosure, the term "cable" refers to a rope, cable or wire or other stress member to which a node may be attached.

In various examples and embodiments, a suitable seismic node deployment system may include a cable supply configured to provide a cable, wherein one or more nodes are configured to be coupled to the cable for deployment to a water column. The node attachment system is configured to drive a portion of the cable to move periodically between the cable supply and the water column such that a velocity of the cable is substantially reduced for attaching the seismic node relative to a velocity of paying out the cable into the water and deploying the seismic node. For the purposes of this disclosure, the terms "periodic" and "periodic motion" are not limited in meaning to regular, periodic, or fixed intervals, but should be broadly construed to also include only recurring or intermittent intervals that are variable and have no fixed or regular time range between occurrences.

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. A broader presentation of the features, details, utilities, and advantages of the present invention as defined in the claims is provided in the following written description of various embodiments and implementations and is shown in the accompanying drawings.

Drawings

FIG. 1 is a schematic diagram of an exemplary seismic survey system configured for acquiring seismic data.

FIG. 2 is a top plan view of a representative seismic node deployment system installed on the rear deck of a seismic survey vessel.

Fig. 3 is a side perspective view of a node deployment system having a single-pass cable management configuration.

Fig. 4 is a simplified schematic diagram of the node deployment system of fig. 3.

Fig. 5 is a schematic diagram of a nodal deployment system in a two-pass fixed pulley configuration.

FIG. 6 is a schematic view of the node deployment system of FIG. 5 with a movable carriage.

FIG. 7 is a top plan view of the multi-cable seismic deployment system installed on the rear deck of a seismic survey vessel.

FIG. 8 is a block diagram illustrating a seismic node deployment method.

Fig. 9A-9D are schematic diagrams depicting the functional steps of an embodiment of seismic node attachment and deployment.

10A-10C are schematic diagrams depicting the functional steps of an embodiment of seismic node retrieval and separation.

FIG. 11A is an isometric view of an embodiment of a system for seismic node deployment and retrieval that performs the functional steps of FIGS. 9A-10C.

Fig. 11B is a top plan view of the system of fig. 11A.

FIG. 12 is a flowchart of the operational steps performed by the control system controlling seismic node attachment and deployment according to FIGS. 9A-9D.

FIG. 13 is a flowchart of the operational steps performed by the control system controlling seismic node retrieval and separation according to FIGS. 10A-10C.

Detailed Description

In this disclosure, reference may be made to various examples and embodiments of the invention. The scope of the claims is not limited to these specific examples nor to any other specifically identified or enumerated embodiments, unless recited in claim language. Any combination of the disclosed features may be suitable for practicing the invention, whether in the context of a single example or in various embodiments as defined within the scope of the claims.

Although some examples and embodiments may achieve various advantages over the prior art and other more modern solutions, these advantages do not limit the scope of the claims unless expressly recited therein. The aspects, features and advantages of the disclosed examples and embodiments are merely illustrative and reference to a particular feature of the invention in the specification should not be considered as a generalization of any embodiment claimed unless such functionality is explicitly included in the claim language.

Seismic survey deployment

Fig. 1 shows a representative seismic survey (or survey system) 100 in which an array of seismic receivers or autonomous nodes 110 are deployed along one or more ropes or cables 115 to a water column 120. Water column 120 extends from top surface 122 to the sea floor or other bottom surface 124 above an oil reservoir or other subsurface structure 126 of interest in seismic surveying.

Depending on the application, a cable or cable 115 may be towed through the water column 120 behind one or more seismic survey vessels 130 using a suitably adapted seismic survey deployment system 150. A suitable seismic survey vessel 130 may also be configured to deploy the nodes 110 to the seabed or other bottom surface 124, for example, with the nodes 110 distributed along individual cables 115 above a reservoir or other subterranean structure 126, as shown in fig. 1. The nodes 110 may be seismic nodes, receivers, or other autonomous sensing devices attached along the cable 115, or acoustic transmitters or other transponders alternatively or additionally for location identification or other information transmission. Node 110 may also be suspended deep in water column 120 between top surface 122 and the sea floor or sea bed 124, or a combination of subsea cable 115, tow node 110, and suspended node 110 may be deployed.

Although the seafloor or seabed may be referenced with respect to this particular example, node deployment according to the present disclosure is not necessarily limited to any particular body of water or other seismic medium 120. Rather, the nodes 110 may be deployed to any body of water, ocean, land-based, or other seismic environment 120, including oceans, lakes, rivers, and the like. Thus, the use of the terms sea, sea bed, sea floor, etc. should be broadly understood to encompass all bodies of water 120 suitable for deployment of the nodes, as well as all ocean or land-based surfaces 124, to detect propagating seismic energy or other signals or energy recordable by any type of sensor that may be packaged as a node.

In some embodiments, the individual cables 115 may be made of a synthetic or metallic material having a predetermined specific density relative to the water column 120 in which the cables 115 are immersed. In some embodiments, the individual cables 115 may have a passive cable configuration, e.g., no internal electrical conductors or other hardwired signal elements. In other embodiments, the cable 115 may include embedded conductors for conveying one or more of clock signals, data signals, control signals, and power between individual seismic nodes or receivers 110. Thus, each cable 130 may have a passive configuration, i.e., no signal or power connection between individual receivers or nodes 110 distributed along each cable 115; or an active configuration in which signal and/or power connections are provided between receivers or nodes 110.

In particular embodiments, the nodes 110 may be deployed via an autonomous or remotely operated seismic survey vessel 130 operating on the surface 122, or at a selected depth within the water column 120, or on the bottom surface 124. In other examples, one or more nodes 110 may be equipped with a steering, propulsion, and/or recovery system adapted to navigate nodes 110 through water column 120 when disposed along cable 115, or to recover nodes 110 and cable 115 from water column 120.

The seismic nodes 110 may also be configured for external communication when deployed in the water column 120, for example, via end devices or repeaters 145 deployed along the cable 115, with wired or wireless (e.g., acoustic, inductive, or capacitive) data connections to a seismic hub or buoy system 140. Wireless data communication may also be provided directly between the individual nodes 120 and the seismic survey vessel 130 and between the seismic survey vessel 130 and one or more hub devices 140.

A suitable hub device 140 may be equipped with a Global Positioning Satellite (GPS) system or other positioning or navigation system to determine the location and timing data of the node 110. A suitably configured hub 140 or "master" node station 145 may also be provided with a high precision master clock to synchronize timing information of the seismic nodes 110 disposed along each respective cable 115.

The appropriate hub 140 or master node station 145 may also be equipped with power generation equipment, energy storage equipment and control logic for quality checking of seismic data collected by the individual receivers of the node 110, and operational commands selected to perform quality and station health tests, communicate a priority subset of the seismic data, turn the node 110 on or off, or enter a power saving mode.

Seismic data acquisition

In operation of the seismic survey 100, one or more seismic survey vessels 130 may be configured to tow seismic sources 125 (or source arrays) 125, alone or in combination with an array of seismic receivers or nodes 110 disposed along one or more tow cables, streamers, or node lines 115. Alternatively or in combination, the node 110 may also be deployed in an array of one or more subsea cables 115, for example as provided on the bottom surface 124 of the water column 120, or below the top surface 122 and at a selected depth above the bottom surface 124. The seismic cable 115 thus includes various towed streamer, ocean bottom cable, and floating cable embodiments as well as marine-based seismic system configurations.

Similarly, depending on the desired configuration of the seismic survey system 100, multiple source or other seismic survey vessels 130 may be employed, and the cables 115 may be arranged in a combination of towed, seafloor, and suspended seismic arrays. In multiple vessel embodiments, the multiple towed sources 125 may be configured to operate independently or to emit seismic energy 142 at substantially the same time in a coordinated manner, for example, according to a simultaneous source scheme.

Depending on the embodiment, each source device 125 may include one or more seismic source components configured to generate seismic energy in the form of acoustic waves 142 that propagate through the water column 120. For example, the airgun array or subarray 125 may be configured to generate acoustic waves 142 by emitting a controlled blast of compressed air, or other pneumatic, mechanical, or electromechanical power components 125 may be used.

A portion of the seismic waves 142 propagating down through the water column 120 will penetrate the seafloor 124 and reflect from an oil reservoir or other subterranean geologic structure 126. A portion of the reflected seismic energy may propagate through the seafloor 124 back to the seismic nodes 110 deployed along one or more ocean bottom cables 115 and back up through the water column 120 to receivers or nodes 110 disposed along one or more cables 115 towed or suspended at the depth of the water column 120 by the seismic survey vessel 130.

Reflections also occur at both the top surface 122 and the bottom surface 124, resulting in a complex combination of upwardly and downwardly propagating seismic wave field components. Thus, deghosting and other advanced processing techniques are applied to the resulting seismic data acquired by the nodes 110 to generate images of the subsurface layers and other related geological structures. The images may be analyzed by geologists, engineers, and other industrial users to identify relevant characteristics of the subsurface reservoir 126 and other geological structures that may include hydrocarbons or other natural resources, and to locate and characterize other subsurface geology of interest.

Seismic node deployment

In many cases, it may be preferable to attach the seismic nodes 110 to the cable 115 when the receiver sensor array is deployed, and to detach the nodes 110 from the cable 115 when the receiver sensor array is retrieved. This provides a number of advantages. First, once the node 110 is removed, the cable 115 can be easily wound on a spool. If the node 110 is permanently attached to the cable 115, it would be difficult to store the cable 115 without damaging the node 110. Additionally, it would be difficult to pass the cable 115 with the attached node 110 through the directional and drive pulleys necessary to deploy the cable 115 into the water column 120 and retrieve the cable 115 from the water column 120. Furthermore, if the node 110 is disconnected from the cable 115, it may become very easy to clean, maintain, recharge, and download data from the node 110. For example, once detached, the node 110 may be placed into a charging station and a data download station. This would be extremely difficult if node 110 remained attached to cable 15.

FIG. 2 is a top plan view showing a representative seismic survey deployment system 150 installed, for example, on the rear deck area 135 of a seismic survey vessel 130. Depending on the embodiment, the seismic survey deployment system 150 may include a cable spool, winch, or cable supply 155 for the corresponding cable 115 with a node handling and attachment system 160 including a cable buffer device 200 for attaching the node 110 to the cable 115, for example, disposed between front and rear cable guides or sheaves 170 and 175. The node location/retrieval mechanism 165 may be configured to position the seismic node 110 relative to the cable 115 for attachment and detachment, and the power sheave system 180 may be configured to control the velocity and tension of the cable 115 as the node 110 is deployed to and retrieved from the water column 120.

In some embodiments, a single cable type node deployment system 150 may be provided, and the seismic survey vessel 130 may take the form of a chase ship or an Unmanned Autonomous Vehicle (UAV). Alternatively, multiple deployment systems may be deployed on the aft deck of the seismic vessel 130 to deploy the array of seismic nodes 110 on multiple ropes or cables 115, as described below.

As shown in fig. 2, the spool system 155 supplies the ropes or cables 115 to the respective node attachment systems 160 via one or more front cable guides or pulleys 170. The nodes 110 are attached to selected locations along each cable 115 via a node attachment system 160 and are deployed along the cables 115, the cables 115 extending from the node attachment system 160 to the sheaves 180 via one or more rear cable guides or pulleys 175. Alternatively, cable 115 may extend substantially directly from spool 155 to nodal attachment system 160, or from nodal attachment system 160 to sheave 180, or both, and may not utilize one or more of cable guides or pulleys 170 and 175.

The sheave system 180 manages tension in the cable 115 when the node 110 is deployed to or retrieved from the water column 120 with the node 110 disposed in a selected position along the cable 115. In some examples, the node 110 is deployed when the cable 115 is payed out over the aft end or stern 136 of the seismic vessel 130, as shown in fig. 2. The nodes 110 and cables 115 may also be paid out and deployed on the side or bow of the vessel 130.

Node attachment system 160 is configured to manage the speed of cable 115 when node 110 is attached. In the particular embodiment of fig. 2 and 3, the cable buffering device 200 of the node attachment system 160 utilizes a reciprocating carriage and pulley mechanism configured to be modifiedThe speed of the variable cable 115 at the node attachment location (or attachment point A) with the carriage 210 at a reciprocating speed V_RMove back and forth to attach node 110 to cable 115 at substantially zero relative velocity or at a substantially reduced velocity compared to a cable over-the-board (overboading) velocity, as described herein.

Velocity generally refers to the absolute value or magnitude of a given velocity, while the velocity may be positive, negative, or zero. For reciprocating members such as carriage 210, the speed may also be based on a maximum value V_RTo quantify, but it should be understood that carriage velocity is at positive and negative values ± V_RTo change between. Similarly, amplitude A_RCan be used to describe the maximum absolute displacement while the position of the carriage 210 is at + -A_RTo change between. Speed (speed) and speed (velocity) may also sometimes be used interchangeably depending on the context, and these terms should not be construed as being limited to any particular definition unless explicitly stated.

More generally, the attachment speed traveled by the cable 115 when the node 110 is attached may be in accordance with a cable delivery speed v of the cable 115 provided by the spool 155₁Significantly different from, and in contrast to, the cable over-board velocity v at which the cable 115 is paid out into the water column 120₂Is significantly different. In some embodiments, for example, the cable delivery velocity v₁And the over board velocity v₂May be substantially the same, e.g., in a range of up to about 2.5m/s or more, as the sailing speed v of the vessel 130 relative to the surrounding water column 120 as the nodes 110 are deployed along the cable 115₀And (5) the consistency is achieved. Alternatively, the speed of travel may vary, for example, from about 1m/s or less to about 5m/s or more, or from about 2 knots to about 10 knots.

However, in contrast to other designs, node attachment mechanism 160 is configured to vary the speed of cable 115 at attachment point a such that node 110 may be attached when an adjacent portion of cable 115 travels at a significantly lower relative speed or substantially zero speed (e.g., as measured relative to rear deck 135).

The nodal attachment system 160 also serves as a cable buffer system that can be used to stop or slow the cable 115 at selected locations, thereby controlling the on-board length of the cable 115 to manage and maintain tension without substantially changing the overboard or recovery speed at the sheave or winch 180 or the cable spool payout speed at the spool 155. For example, if the cable 115 or node 110 is pinched or stuck on an object during deployment or retrieval, or if the node is not properly attached or detached, the cable buffering device 200 may be used to manage the length and tension of the cable 115 until an obstruction along the cable 115 or node 110 is released, or other corrective action may be taken.

Accordingly, the buffer rope length in the cable buffer device 200 may be managed to reduce tension and stress on the spool, winch and sheave members 155 and 180 and/or to control or maintain a substantially constant tension and/or speed of payout at the spool 155 and/or deployment/retrieval at the sheave 180. In certain applications, an obstacle or other obstruction may be disposed along the cable 115, such as an improperly attached or detached node 110, wherein the cable buffering device 200 is configured to manage the buffering length of the cable 115 in order to maintain the speed or tension at which the cable supply 155 provides the cable 115, or the speed or tension at which the sheave or winch 180 deploys or withdraws the cable 115 from the water column, or both, while detaching the obstacle or other obstruction. In general, winch speeds in conjunction with one or more of the buffer devices 200 may be adjusted to facilitate attachment and detachment of the nodes and to manage removal of obstacles or other obstacles on the cable 115.

For example, node attachment system 160 may be provided with reciprocating carriage and pulley mechanism 210 that is positioned at a position amplitude a_RAnd at a maximum velocity V of about half of the over-board velocity_R（V_R≈±1/2V₁) Travel back and forth. In this embodiment, when node 110 is attached, the attachment speed may be approximately zero, as defined by the speed of cable 115 at attachment point or location a. Alternatively, reciprocating carriage speed V_RCan vary and the speed of attachment will vary accordingly. More generally, the velocity of the cable 115 may be substantially reduced relative to the node 110 due to the reciprocating motion of the cable carrier device 210, or the cable 115 may be at a velocity V from the reciprocating motion_RAnd defined by the amplitude ARSubstantially stop for a period of time, thereby facilitating a secure and secure attachment of the node 110 to the cable 115.

With the speed v of the beam passing₂In contrast, the delivery or payout speed v may also be relative to the cable₁Limiting reciprocating or alternate carriage speed V_RMaximum absolute value of (V)_R. On average, the delivery and payout rates of the cable may be substantially the same (i.e., v₁≈v₂) And, in one embodiment, cable delivery velocity v during deployment of node 110 into water column 120₁And the over board velocity v₂Can remain substantially constant and they may be related to the speed v of the ship 130₀Substantially similar. In an alternative embodiment, the overboard velocity v₂Can be kept substantially constant while the cable delivery speed v₁May be varied to facilitate the reciprocal movement of the cable carrier device 210 and the attachment of the node 110 to the cable 115.

FIG. 3 is a side view of a deployment system 150 deployed on the aft deck 135 of a seismic survey vessel 130 with a single-pass node attachment system or device 160. As shown in fig. 3, a winch or spool system 155 provides the cable 115 to the node attachment system 160 via one or more cable guides or pulleys 170. The cable 115 makes a single pass through the cable buffering device 200, for example, between first and second pulleys 220 attached to a reciprocating bracket or frame 210.

The node 110 is positioned near the cable 115 by the positioning and retrieving device 165, and the node is attached to the cable 115 when an adjacent portion of the cable 115 has a desired velocity. For example, cable payout speed V when the adjacent section is substantially stationary relative to the aft deck 135, or at the same time as spool system 155₁Over board velocity V compared to, or deployed into, water column 122 along cable 115 relative to node 110₂In terms of substantially reduced speed, the node 110 may be attached to the cable 115 via a clamping mechanism or lanyard.

As shown in FIG. 3, the magnitude of the relative velocity of the cable 115 adjacent to the seismic node 110 depends on the reciprocation velocity V_RAnd the number of times the cable 115 passes over the pulley 220. The relative speed also varies during the reciprocating cycle fromBut increases or decreases depending on the speed and direction of movement of the carriage 210.

In the "single pass" configuration of figure 3, the cable 115 passes over a first (single) pulley 220 at one end of the reciprocating carriage 210 and over a second (single) pulley at the opposite end of the reciprocating carriage 210. As the carriage 210 reciprocates, the cable is taken up or released on both sides of the respective pulley 220 depending on the direction of motion. If the reciprocating speed V_RThe magnitude of (a) being the cable pay-out speed v₁(or overboard velocity v)₂) Half of the length of the cable 115, the portion of the cable 115 adjacent the node will therefore be stationary for at least part of the reciprocation cycle. By speed V of reciprocating movement, as opposed to sinusoidal or harmonic form_RSelecting a substantially square wave form, the period of relative velocity to zero (or substantially reduced) may be increased as part of the reciprocation cycle.

Depending on the deployment speed and reciprocation amplitude, this may provide a window of about one-quarter or more of the reciprocation period during which the node 110 may be attached to the cable 115 at substantially zero relative speed; that is, while both nodes 110 and adjacent portions of cable 115 are substantially stationary relative to aft deck 135. Alternatively, the reciprocating waveform may be harmonic, and node 110 may be attached at a relative velocity minimum defined during movement of carriage 210, e.g., when the carriage moves up or down (depending on the configuration) relative to aft deck 135, and cable 115 is substantially stationary relative to node 110 at attachment point a.

In other embodiments, the relative attachment speed may be selected to be substantially lower than the cable payout speed v as defined at the spool 155₁Or over board velocity v defined aft of sheave system 180₂. More generally, during the reciprocation cycle of the carriage 210, the relative velocity of the cable adjacent to the attachment location a varies between different points of higher and lower values, and the attachment velocity may be selected accordingly.

Fig. 4 is a simplified schematic diagram of the node deployment system of fig. 3. As shown in fig. 4, the nodal attachment system 160 is provided in a single pass arrangement, with two pulleys 220 provided at opposite ends of a shuttle table or plate-type carriage 210. Although the carriage 210 is shown in a horizontal orientation relative to the rear deck 135 in fig. 3, this is a matter of drawing convention, and both horizontal and vertical orientations are contemplated. Similarly, although the reciprocating direction is shown as being generally perpendicular or normal to the entire path of the cable 115 between the spool supply 155 and the sheave 180, longitudinal, transverse, and skew orientations are contemplated.

A mechanical drive system 400 is also shown and is configured to measure V at a speed_RThe drive carriage 210 reciprocates in magnitude as defined relative to the rear deck and stationary components such as the cable spool system 155 and the sheave 180. The driver 400 may be configured to drive the carriage 210 in a periodic motion having a substantially square, saw-tooth, or other non-sinusoidal velocity or position waveform so as to increase the portion of the reciprocating motion cycle during which the cable 115 is substantially stationary adjacent the node 110 at attachment point a. Alternatively, the reciprocating motion may be substantially harmonic and sinusoidal. In other embodiments, the periodic motion may occur at variable or intermittent intervals, with no fixed or regular time range between occurrences, but rather according to a command for signaling to attach node 110.

In one embodiment, the driver 400 may be configured to execute a single reciprocation cycle upon receiving a command from the control system to control node deployment to facilitate node attachment. A series of such commands may be issued at varying or consistent intervals in order to attach the node 110 at a desired location on the cable 115. Similarly, the cable spool system 155 can also be controlled to vary the supply rate of the cable 115 in coordination with the movement of the carriage 210 as determined by the drive system 400, or the supply rate can be substantially constant during deployment, as described above.

Driver 400 may also be configured to adjust the period of reciprocation to attach nodes 110 at desired intervals along cable 115. Both the magnitude of the reciprocating velocity and the magnitude of the motion may also be adjusted based on the payout and over-board velocity of the cable 115, and the desired time window for attaching the node 110 at the desired location along the cable 115 at the desired relative velocity.

Figure 5 is a schematic of the node deployment system 150 in a configuration in which the fixed pulley 225 is attached to the stationary structural member 215 and the moving pulley 220 is attached to the reciprocating carriage 210. This is a two-pass embodiment in which the carriage 210 reciprocates at about one-quarter of the cable payout or over board speed (e.g., V)_R≈v₁/4 or V_R≈v₂In case/4), a substantially zero cable speed can be achieved at the attachment point a. As described above, a mechanical drive system 400 is provided to drive the carriage 210 in a reciprocating motion having a desired amplitude, period, and cyclic waveform.

Figure 6 is a schematic diagram of the node deployment system 150 in a two-pass configuration, in which four pulleys 220 are fixed to the reciprocating carriage 210. Similar to the two-pass, fixed-pulley embodiment of fig. 5, a suitable mechanical drive 400 may be configured to assume a cable payout speed v₁Or over board velocity v₂About one quarter of the reciprocating speed magnitude V_RCarriage 210 is driven to provide a time window within the reciprocation period within which a portion of cable 115 is substantially stationary adjacent node 110 at attachment point a.

The two-pass configuration of fig. 6 operates similarly to the single-pass configuration of fig. 5. An additional feature is that there are multiple positions B, C, D at which position B, C, D the cable 115 will have a much lower relative velocity (or substantially zero velocity) with respect to the rear deck 135 during a particular phase of the carriage 210's reciprocating motion. As shown in fig. 5, for example, there are stages where the rope or cable 115 may have a lower or zero velocity relative to the node 110 at attachment point a. This is because as carriage 210 moves toward clamp 215, left lower sheave 220 loses slack, which must pass through node attachment system 200 and over the board. In fig. 6, node 110 may be attached at any one of locations B, C and D. This is because the slack lost by the lower left pulley 220 can be picked up by the upper right pulley 220.

Fig. 7 is a top plan view of the multi-cable seismic deployment system 150 installed on the rear deck of a seismic survey vessel. As shown in fig. 7, deployment system 150 may include a plurality of two or more separate cable supply systems 155, with respective node processing systems 160 configured to store and provide a plurality of nodes 110 for attachment to respective plurality of cables 115.

In such an arrangement, the nodal attachment system 160 may be longitudinally oriented with the carriage 210 substantially along the primary path of each cable 115 between the respective cable supply spool 155 and the sheave system 180 at a velocity V_RAnd (4) reciprocating. Alternatively, the reciprocating motion may be substantially vertical, oblique, or transverse relative to the front and rear portions of the cable 115, and either horizontal or vertical relative to the rear deck 135, as described above.

More generally, the deployment system 150 may be adapted to provide one or more attachment locations at which the relative velocity of the cable 115 relative to the node 110 and the aft deck 130 is substantially zero, or substantially less than the over-board velocity, within a selected time window during the reciprocation cycle. The time window depends on the carriage speed and displacement amplitude and may range from a transient or temporary attachment window ranging from a few percent of the reciprocating cycle to as much as 10% to 25% of the cycle, or from 25% to as much as 50% or more depending on the time profile of the reciprocating motion.

The pulley and guide arrangement may also be adapted to reduce the maximum reciprocation speed V of the carriage 210_RWhich is a value in absolute terms relative to the rear deck 135 and as a cable delivery speed v₁And the over board velocity v₂A part of (a). More generally, the time window for the relative velocity of the cable 115 to decrease near each attachment location A, B, C, D may increase to the following absolute range: up to 1-2 seconds or more, up to 2-5 seconds or more, up to 5-10 seconds or more, or up to 10-15 seconds or more, depending on the carriage speed and displacement amplitude and the time profile of the reciprocating motion, as described above.

Further, the sheave and guide configuration may be adapted to provide a plurality of attachment points A, B, C, D for staged sequential attachment of nodes at selected locations along the cable 115, thereby increasing deployment efficiency for a seismic array configuration having a large number of nodes 110. The location may also be selected to reduce interference between the attached node 110 and the pulley system, such as by selected placement on the carriage 210, or by using a combination of fixed and reciprocating pulley members, as shown in fig. 5.

The carriage and pulley arrangement may also be configured such that the maximum reciprocation speed V of the carriage 210_RCable velocity v for deployment of seismic nodes₂About half or less, or the cable supply delivery speed v₁E.g., in a single pass configuration. Maximum reciprocation velocity V_ROr the cable delivery speed V₁Or over board velocity V₂About one-quarter or less, for example in a two-pass configuration. More generally, the cable buffering device 200 may be configured with a combination of a pulley 220 attached to the bracket 210 and a stationary pulley 225 attached to the stationary clamp 215 such that the maximum reciprocating velocity V of the bracket 210_RIs 1/n or less of the cable speed at which the seismic node is deployed, such as where n is between two and eight (including the endpoints), or n is eight or more.

FIG. 8 is a block diagram illustrating a method 300 of seismic node deployment, for example, according to the deployment system 150 described herein. As shown in fig. 8, the method 300 includes one or more of the following: providing a cable (step 310), paying out an end of the cable to a water column (step 320), driving a portion of the cable in a reciprocating motion (step 330), and coupling one or more seismic nodes to the cable (step 340) for deployment (step 350), wherein an attachment velocity may be reduced relative to an overboard velocity of the paid out cable end. These steps may be performed in any order or combination, with or without one or more additional steps, such as buffering the cable and controlling tension in the cable (step 360), controlling the speed at which the cable is provided (step 370), and retrieving the node (step 380), as well as any additional steps described herein.

Providing the cable (step 310) may be performed with a cable spool, winch, or similar cable supplier. The end of the cable may be paid out into the water using a sheave system (step 320).

A portion of the cable is driven in a reciprocating motion relative to the end paid out into the water (step 330) such that the relative velocity of the cable portion to which the node is attached (step 340) is reduced relative to the over-board velocity at which the cable is paid out and the node is deployed (step 350). Tension can be controlled by damping the cable prior to deployment via a sheave system (step 360), for example, disposed in a reciprocating manner between the water column and the cable section. The speed of the supply cable may also be controlled (step 370), for example, to adjust the tension in the cable portion to which the adjustment point is attached.

One or more seismic nodes are coupled or attached to the cable portion at a reduced attachment speed (step 340) such that the attached seismic nodes are deployable into the water on the cable. For example, when a seismic node is coupled to an adjacent portion of a cable, the attachment velocity may be reduced to substantially zero relative to the seismic node or the rear deck region.

The node attachment and deployment device may also be used to buffer the rope or cable length (step 160) and may be used to stop or slow down the cable to manage and maintain speed and tension (steps 160, 170). For example, bumpers may be used to maintain payout and over board/recovery speeds and tensions substantially constant while changing speeds and tensions at other locations on deck, as described herein. In certain applications, obstacles or other obstacles may be formed or disposed along the cable, and buffering may be applied to manage the length of the cable so as to maintain the speed and tension at which the cable is provided or deployed to or retrieved from the water column, while clear of the obstacles or other obstacles.

For example, a rope or cable (or a node on a rope or cable) may be caught or stuck on something in the water or on a boat. The nodes may also be improperly engaged or disengaged, thereby creating an obstruction along the length of the cable. In this case, buffering can be used to manage cable length and cable speed and tension until the cable or node is released, disengaged from the obstruction, and other corrective action can be taken. Cable buffer length may also be managed to reduce tension and stress on the payout spool and/or on the deployment winch or sheave, and to maintain constant payout speed and/or tension during node deployment and retrieval while maintaining personnel and equipment safety. In prior art systems without a damping device, sudden changes in cable speed and tension may not be desirable in order to remove obstructions and other obstacles, and it may be more difficult to accommodate such changes when sudden changes occur without increasing the risk of equipment damage or loss.

An alternative embodiment of a seismic node deployment system 500 is depicted in fig. 9A-10C. The system 500 is configured to attach and detach a plurality of seismic receiver nodes 504 to and from a cable 502 for deployment from and return to a marine vessel. Nodes 504 may be seismic nodes, receivers, or other autonomous sensing devices, or alternatively or additionally, acoustic transmitters or other repeaters attached at spaced apart locations along cable 502 for location identification or other information transmission. The system 500 may include a front bumper system 506 and a rear bumper system 508 for controlling the relative velocity of the cable 502 relative to a node coupling apparatus 510 for attaching and detaching the plurality of nodes 504 to and from the cable 502 in spaced apart locations. Front and rear bumper systems 506, 508 may temporarily steer portions of cable 502 periodically to take up and pay out portions of cable 502 to reduce the speed of the portion for node attachment. In some embodiments, the periodic turning of the cables 502 in the front and rear bumper systems 506, 508 may be performed at regular intervals. In other embodiments, the periodic steering may occur at intermittent intervals without a fixed or regular time range between occurrences, but rather at commands that signal to attach node 504 to cable 502 or detach from cable 502.

The cable 502 may be stored on a storage reel or spool 512 from which the cable 502 is paid out for deployment in a water column or wound for storage when not in use. A traction winch or cable tensioner 514 may be positioned between the front and rear bumper systems 506, 508 to maintain proper tension on the cable 502 when paying out or pulling back the cable 502. The node coupling device 510 may be positioned between the cable tensioner 514 and the rear bumper system 508.

The front bumper system 506 may include a front pinion pulley 514 that travels laterally on a lateral rack 516. In some embodiments, a drive motor may be attached to the front pinion pulley 514 and configured to move the front pinion pulley 514 back and forth along the transverse rack 516. The rear bumper system 508 may include a first rear base pulley 520 and a second rear base pulley 522, both fixedly positioned adjacent to the base of a vertical rack 528. The first rear base pulley 520 may be positioned on a front side of the vertical rack 528, and the second rear base pulley 522 may be positioned on a rear side of the vertical rack 526. Rear pinion pulley 524 may be movably attached to vertical rack 526 and aligned between first rear base pulley 520 and second rear base pulley 522. In some embodiments, a drive motor may be attached to the rear pinion pulley 524 and configured to move the rear pinion pulley 524 up and down along the vertical rack 526.

An exemplary deployment operation of the system 500 is depicted in the series of fig. 9A-9D. To prepare the system 500 for operation, the cable 502 must be unwound from the spool 512 and threaded through the components. Spool 512 may be manually driven as cable 502 is threaded through system 500, i.e., through forward damping system 506, cable tensioner 514, node coupling device 510, aft damping system 508, and through over board devices (not shown in the schematic diagrams of fig. 9A-9D). An end counterweight may be connected to the first end of cable 502, typically using a deck crane (not shown).

Initially, as shown in FIG. 9A, the cable 502 is unwound from storage on the spool 512 and threaded around the front pinion pulley 516. The spool 512 is typically driven by an electric motor and functions as a capstan when the cable 502 is wound and unwound from the spool 512 due to the large mass of the cable 502 and the associated torque generated as the spool 512 rotates. When the cable 502 is unwound from the spool 512, the spool 512 provides tension on the cable 512 as the cable is paid out. The front pinion pulley 516 is movably mounted on a transverse rack 518 and may be driven transversely along the transverse rack 518 by a motor (not shown) under the control of a control system described further herein. In one exemplary embodiment, the transverse rack 518 may include a linear array of gear teeth along its length, and the motor may rotate a gear engaged with the linear gear teeth to move the front pinion pulley 516 back and forth on the transverse rack 518.

After wrapping around the front pinion pulley 516, the cable 502 then passes through a cable tensioner 514 that pulls the cable 502 from the spool 512 at a speed synchronized with the boat speed. The cable tensioner 514 may consist of one or more pulleys through which the cable 502 passes and which are configured to provide the appropriate tension on the cable 502 when deploying and retrieving the cable 502 from the water column. One or more of the pulleys forming the cable tensioner 514 may be driven by a motor through a suitable transmission to protect the front pinion pulley 516 and the spool 512 from excessive forces that may be imparted on the cable 502 by the water column.

The cable 502 next passes through a node coupling device 510 configured to attach a plurality of sensor nodes 504 to the cable 502 in series, typically at regular spaced intervals (and further to decouple the nodes 504 from the cable 502 in reverse operation). In an exemplary embodiment, each node 504 may be equipped with a spring-loaded coupling that clamps the node 504 to the cable 502. The node attachment device 510 may be configured to: the node 504 is picked from the supply of the node 504 provided, the spring clip is compressed, placed around the cable 502, and released to connect the node 504 to the cable 502.

After passing through the node coupling device 510, the cable 502 may be threaded through a plurality of pulleys that form a rear cable buffer 508. The first and second rear base pulleys 520, 522 may be located at fixed positions on lateral sides of the base of a vertical rack 526 along which the rear pinion pulley 524 moves. The rear pinion pulley 524 may be driven vertically along a vertical rack 526 by a motor (not shown) under the control of a control system as further described herein. In one exemplary embodiment, the vertical rack 526 may include a linear array of gear teeth along its length, and the motor may rotate a gear engaged with the linear gear teeth to move the rear pinion pulley 516 up and down on the vertical rack 526.

As shown in fig. 9A-9D, the cable 502 may pass under each of the first and second rear base pulleys 502, 522 and over the rear pinion pulley 516. At the lower or base end of vertical rack 526, rear pinion pulley 516 may pass between each of first rear base pulley 502 and second rear base pulley 522 to a low point of vertical travel thereof and out of contact with cable 502. After passing through the rear cable buffer 508, the cable 502 with attached node 504 may be deployed into the water column via an overboard unit (not shown).

Upon system startup, the selected spool 512 will enter a tensioning mode and the cable tensioner 514 will begin to pull the cable 502 from the spool 512 at a cable speed synchronized with the boat speed. The rear bumper 508 will accumulate the maximum amount of cable length by moving to its upper position. Under the signal for "attach node", the rear buffer 508 will begin to pay out from the accumulated length, thereby maintaining a steady cable speed being paid out from the vessel. At the same time, the front bumper 506 will begin to accumulate cable by moving forward and thereby maintain a steady cable speed exiting from the spool 512. This will together hold the cable 502 stationary in the node coupling device 510 for a sufficient time to attach the node 504 to the cable 502. When the aft damper 508 reaches its fully down or "open" position, the forward damper 506 will stop and the cable 502 with the node 504 connected thereto will move toward the over board unit. Once the system 500 detects that the node 504 has traversed the area of the back buffer 508, the front buffer 506 will move to its back position and the back buffer 508 will begin to accumulate cables at a synchronous speed. Once the rear bumper 508 has accumulated the maximum length of cable 502 by reaching the upper position, the system 500 is ready to attach another node 504.

The configuration and operation for deployment of cable 502 and attachment of node 504 as generally described above is shown in more detail in fig. 9A-9D. The front pinion pulley 516 begins in a rear position along the transverse rack 518, and the rear pinion pulley 524 begins in an upper position on the vertical rack 526. The cable tensioner 514 begins to pull the cable at a constant speed. Thus, the cable 502 is unwound from the spool 512 such that it travels linearly at a constant speed V. In some embodiments, the linear velocity of the cable 502 may be up to 5 knots (2.5 m/s). When it is determined that the appropriate separation distance along the cable 502 between nodes 504 is reached, the front pinion pulley 516 begins to move forward on the front rack 518 at about the speed of the Z V to thereby take up the length of cable 502 unwound from the spool 512. At the same time, rear pinion pulley 524 begins to move downward on vertical rack 526 at approximately the speed of 123V to thereby pay out cable 502, which previously extended along vertical rack 526, to pass over the board at speed V (overboard). When the front and rear pinion pulleys 516 and 524 move in their respective directions at half the speed of the cable 502 as it is paid out, the relative speed of the cable 502 with respect to the node coupling device 510 is 0V, i.e., the portion of the cable 502 that passes through the node coupling device 510 does not actually move in this frame of reference.

By effectively stopping the movement of the cable 502 through the node coupling device 510, the node 504 can be easily attached to the cable 502 at a desired location during which time the front and rear pinion pulleys 516 and 524 traverse the length of the transverse and vertical racks 518 and 526, respectively. Typically, if the overboard velocity V is 5 knots (2.5 m/s), for example, the time for such traversal is on the order of a few seconds, depending on the length of the racks 518, 526 and the velocity of the cable 502. This is sufficient time for: the node coupling device 510 picks up the node 504 from the supply, compresses the spring clip, places the open clip around the cable 502, and releases the spring clip on the node 504 to complete the attachment of the node to the cable 502.

Once node 504 is attached to cable 502, front pinion pulley 516 and rear pinion pulley 524 have completed their traversal of lateral rack 518 and vertical rack 526, respectively. At this time, the rear pinion pulley 524 is positioned below the first and second rear base pulleys 520 and 522 as shown in fig. 9C and is no longer in contact with the cable 502. As the front and rear pinion pulleys 516, 524 are stationary in the forward and bottom positions on the lateral and vertical racks 518, 526, respectively, the cable 502 continues to be pulled by the cable tensioner 514 and travels through the entire system 500 at a full, constant deployment speed V. As shown, the coupled node 504 is attached to extend from the bottom of the cable 502. In this manner, node 504 does not interfere with either of first rear base pulley 520 and second rear base pulley 522, and node 504 also does not interfere with rear pinion pulley 524, which is positioned a sufficient distance below the path of cable 502 for node 504 to have clearance above the top of rear pinion pulley 524. Also at this point, the new node 504' may be placed in the node coupling device 510 at a location for picking up the new node 504' and placing the new node 504' on the cable 502.

Once node 504 has traveled beyond second rear base pulley 522, front and rear pinion pulleys 516 and 524 begin to travel generally along transverse and vertical racks 518 and 526, respectively, at the speed of a syringe, with a syringe, to their starting positions at front and top positions on transverse and vertical racks 518 and 526, respectively, as shown in FIG. 9D. As front pinion sheave 516 and rear pinion sheave 524 move, cable 502 maintains its over board velocity V at the stern of the marine vessel. Once the front and rear pinion pulleys 516, 524 reach their starting positions, the cable 502 is paid out at a speed V along its length until the control system of the seismic node deployment system 500 determines that the desired separation distance between the nodes 504 is reached, and the attachment cycle begins again, as described above beginning with fig. 9A.

The velocity V at which the cable 502 unwinds from the spool is the same as the velocity V at which the cable 502 exits over the side from the stern of the marine vessel into the water column during the entire node attachment cycle, and remains constant throughout the cable deployment process.

10A-10C depict a node separation process performed by the seismic node deployment system 500. At the beginning of the retrieval of the cable 502 from the seismic medium (e.g., a body of water), the aft bumper 508 will be in a lower or "open" position and the cable tensioner 514 will be reeled into the cable 502 at a speed synchronized with the vessel. The spool 512 will be in a tension mode rotating in the opposite direction to wind up the cable 502. The sensors will detect when the node 504 is proximate to the node coupling device 510. When the node 504 reaches the correct position in the node coupling device 510, the rear buffer 508 will begin to accumulate the cable 502 at a speed synchronized with the vessel, thereby maintaining a steady cable take-up speed out of the water. At the same time, the front bumper 506 will begin moving backward at the same speed, thereby holding the node 504 in a stable position in the node coupling device 510 for a sufficient time to disconnect the node 504 from the cable 502. When the node 504 is disconnected, the front buffer 506 will move forward toward its center position, and the rear buffer 508 will move toward its lower or "open" position. Once the back buffer reaches the "open" position, the system 500 is ready to receive the next node 504.

In more detail, as shown in fig. 10A-10C, to begin the cable retrieval process, the rear pinion pulley 524 is positioned on the vertical rack 526, below the first and second rear base pulleys 520, 522 (as shown in fig. 10A) and out of contact with the cable 502. The front pinion pulley 516 is additionally in a fully forward position on the transverse rack 518. With the front and rear pinion pulleys 516 and 524 stationary in the forward and bottom positions on the transverse and vertical racks 518 and 526, respectively, the cable 502 may be reeled in or onto the vessel through the system 500 at the full deployment speed V. As shown in fig. 10A, the coupled node 504 is attached to extend from the bottom of the cable 502. In this manner, node 504 does not interfere with either of first rear base pulley 520 and second rear base pulley 522, and node 504 also does not interfere with rear pinion pulley 524, which is positioned a sufficient distance below the path of cable 502 for node 504 to have clearance above the top of rear pinion pulley 524.

Once the node 504 on cable 502 reaches the node coupling device 510, the control system causes the front and rear pinion pulleys 516 and 524 to begin traveling along the transverse and vertical racks 518 and 526, respectively, generally at the velocity of the ZE V to stop the node 504 at the node coupling device 510. Even though the portion of cable ahead of the node coupling device 510 is stationary with respect to the node coupling device 510, the cable 502 maintains the boarding speed (orbital velocity) of V at the stern of the marine vessel and similarly maintains the winding speed of V as the front and rear pinion pulleys 516 and 524 move.

The node 504 may be easily disconnected from the cable 502 by effectively stopping the movement of the cable 502 through the node coupling device 510, as indicated in fig. 10B, during which time the front and rear pinion pulleys 516 and 524 traverse the length of the transverse and vertical racks 518 and 526, respectively. Typically, if the overboard velocity V is 5 knots (2.5 m/s), for example, the time for such traversal is on the order of a few seconds. This is sufficient time for: the node coupling device 510 grasps the node 504 on the cable 502, compresses the spring clip, removes the flared clip from around the cable 502, releases the spring clip on the node 504, and places the node 504 away from the cable 502 for storage, charging, data download, cleaning, and the like.

Once the node 504 has been removed from the cable 502, the front pinion pulley 516 begins to move forward from a rearward position along the transverse rack 518 and forms a buffer length of cable 502 for a continuous, constant speed take-up by the spool 512. The rear pinion pulley 524 begins to simultaneously move downward from an upper position on the vertical rack 526 to release the buffer length of its cable 502, which is thus transferred to the front buffer system 506. With this movement, the front and rear pinion pulleys 516, 524 eventually return to their starting positions for node separation during recovery of the cable 502 so that the next node can pass the rear pinion pulley 524 to be positioned in the node coupling device 510, at which point the cycle is repeated. During retrieval, the cable 502 is wound onto the spool 512 at a constant velocity V, which is the same as the take-up velocity of the cable 502 from the water column.

An exemplary embodiment of a seismic node deployment system 600 according to the schematic in fig. 9A-10C is depicted on the aft deck 644 of the marine vessel in fig. 11A-11B. The system 600 is configured to attach a plurality of seismic receiver nodes 604 to the cable 602 and detach from the cable 602 for deployment from and return to a marine vessel. System 600 may include a front buffer system 606 and a rear buffer system 608 for controlling the relative speed of cable 602 with respect to a node coupling device 610. The plurality of cables 602 may be stored on a plurality of spools 612 from which the cables 602 are paid out for deployment in a water column or wound around spools for storage when not in use. A cable tensioner 614 may be positioned between front bumper system 606 and rear bumper system 608 to maintain proper tension on cable 602 as cable 602 is paid out or pulled back. The node coupling device 610 may be positioned between the cable tensioner 614 and the rear bumper system 608.

As the cable 602 is unwound from storage on one of the spools 612, it may be passed around a pulley on the spool apparatus 632 that helps to unwind the cable 602 on the spool 612 and wind the cable 602 on the spool 612. The spool 612 is typically driven by a motor and functions as a capstan when the cable 602 is wound and unwound from the spool 612 due to the large mass of the cable 602 and the associated torque generated as the spool 612 rotates. A pulley on the spooling device 632 travels laterally on the rod to follow the position of the cable 502 as the cable 502 is unwound or wound around the spool 612. Pulleys on the spooling device 632 guide the cable 602 from between the spools 612 to the front buffer system 606, where the cable 602 is threaded around the front pinion pulley 616. Additional fixed front guide pulleys 634 may additionally be used to guide the cable 602 along the front bumper system 606 to the front pinion 616. In one exemplary embodiment, the transverse rack 618 may include a linear array of gear teeth along its length, and the motor may rotate a gear engaged with the linear gear teeth to move the front pinion pulley 616 back and forth over the transverse rack 618.

After wrapping around the front pinion pulley 616, the cable 502 then passes through a cable tensioner 614. The cable tensioner 614 may consist of one or more pulleys around which the cable 602 is threaded and configured to provide the appropriate tension on the cable 602 when deploying and retrieving the cable 602 from the water column. The pulleys may include a motor driven tension drive pulley 640 and a plurality of tension guide pulleys 642. The tension drive pulley 640 may have a transmission to protect the front pinion pulley 616 and spool 612 from excessive forces that may be exerted on the cable 602 by the water column.

The cable 602 next passes through a node coupling device 610 configured to attach a plurality of sensor nodes 604 to the cable 602 in series, typically at regular spaced intervals (and further to decouple the nodes 604 from the cable 602 in reverse operation). The node 604 may be transported from a storage area on a marine vessel to the node coupling apparatus 610 via a conveyor system 636. In some embodiments, the node 604 may be designed as two separate components, e.g., a battery/memory component and a sensor/clock component, that are separate from each other for storage and maintenance. When such a component node configuration is used, the system 600 may include a pinning and depinning station 638 adjacent to the node coupling apparatus 610 to couple node components together prior to attaching the nodes 604 to the cable 602 or to separate node components after removing the nodes 604 from the cable 602. In an exemplary embodiment, the node 604 may be equipped with a spring-loaded coupling that clamps the node 504 to the cable 502. The node attachment device 510 may be configured to: the node 504 is picked from the supply provided for the node 504, the spring clip is compressed, placed around the cable 602, and released to connect the node to the cable 602.

After passing through the node coupling device 610, the cable 602 may be threaded through a plurality of pulleys that form the rear cable buffer 608. The first rear base pulley 620 and the second rear base pulley 622 may be located at fixed positions on lateral sides of the base of a vertical rack 626 along which the rear pinion pulley 624 moves. Rear pinion pulley 624 may be driven vertically along vertical rack 626 by a motor under the control of control system 650. In an exemplary embodiment, the vertical rack 626 may include a linear array of gear teeth along its length, and the motor may rotate a gear engaged with the linear gear teeth to move the rear pinion pulley 616 up and down on the vertical rack 626. Control system 650 may also control front bumper system 606, spool 512, cable tensioners 614, node coupling device 610, and other components of system 600 in order to synchronize the components and balance the forces and loads on system 600.

Other components of system 600 mounted on rear deck 644 may include topside unit 628, high pressure washer unit 648, and deck crane 646. The over board unit 628 may include additional guide pulleys and provide a strong structural framework for guiding the cable 602 over the stern of the marine vessel and into the water column. The high pressure washer unit 648 may be used to purge salt water, mud, and debris from the node 604 and other components in order to maintain and extend the life of such components. The deck crane 646 may be used to move, assemble, or disassemble any components of the system 600 on the rear deck 644.

As indicated in the exemplary embodiments depicted in fig. 11A and 11B, a control system is typically used to actuate and synchronize the various components of the seismic node deployment system. A flow chart of exemplary node deployment operations 700 performed by a control system to coordinate such a seismic node deployment system is shown in fig. 12. Initially, it should be noted that the cable must be routed from storage on the spool through the front buffer system, the tension system, the node coupling device, and the rear buffer system, as indicated in the start configuration state 702. Once the cable is in place within the deployment system, the control system will actuate the motor on the spool to pay out the cable at a constant speed, as indicated in operation 704. In combination, and in some cases simultaneously, the control system will actuate the motor of the driven pulley in the cable tensioner to place the appropriate tension on the cable within the system, as shown in operation 706. After actuation of the spool and cable tensioner, the control system constantly monitors and adjusts the power to the spool motor and cable tensioner motor and the shifting of the transmission affecting the spool motor and cable tensioner motor in order to maintain proper tension on the cable and resist the constantly changing forces on the cable, for example, the force of the moment of the cable mass as the spool rotates and the force from the water column being towed over the length of cable that has been deployed from the marine vessel.

As indicated in operation 708, the control system also monitors the length of cable paid out from the spool in order to identify locations of node placement along the cable. Typically, the nodes will be located and attached at equal separation distances along the cable. However, the control system may be programmed to attach nodes to cables at different separation distances as needed to meet any particular seismic recording requirement. When it is determined that the node attachment position is aligned with the node coupling device, the control system actuates a motor that moves the front and rear pinion pulleys on the rack. The front pinion pulley moves forward and the rear pinion pulley simultaneously moves downward at substantially half the speed at which the cable is paid out from the spool. By moving the front and rear pinion pulleys in this manner to take up cable length on the front end and pay out stored length on the rear end, the cable section at the node coupling arrangement is substantially stationary or moves at a significantly reduced speed relative to the node coupling arrangement during traversal of the rack by the front and rear pinion pulleys.

During periods of cable inactivity relative to the node coupling device, as indicated in operation 712, the control system causes the node coupling device to attach the node to the cable. The control system can control the time available for attaching the node to be about a few seconds depending on the length of the rack and the speed of the cable. This is sufficient time for: the node coupling apparatus picks up a node from a supply, compresses a spring clip, places the flared clip around a cable, and releases the spring clip on the node to complete the node-to-cable attachment. In some embodiments, for example, as shown in fig. 11A and 11B, the control system may also control and coordinate the conveyor system to convey the node to the node coupling device and position it for pick up by the node coupling device.

The control system also monitors the position of the rear pinion pulley on the vertical rack to determine when its position is below the rear base pulley and clears the cable and attached node, as indicated in operation 714. Once the rear pinion pulley reaches this bottom position, its movement is stopped by the control system and the cable moves at a constant speed throughout the deployment system to pass through the rear buffering system with the attached node and continue to the overboard unit for deployment into the water column, as indicated in operation 716. As noted, the speed at which the cable travels through the deployment system is constant at this time with respect to all components of the system (i.e., the speed at which the cable is paid out of the spool is the same as the speed at which the cable enters the water column as it is with respect to the node coupling apparatus).

After the node attached to the cable passes through the rear buffer system, the control system actuates the motor on the front pinion pulley to move it rearward and actuates the motor on the rear pinion pulley to move it upward, as indicated in operation 718. In this way, the front and rear pinion pulleys return to their starting positions on the rack to prepare the deployment system for attachment of the next node.

Fig. 13 is a flow chart describing an exemplary retrieval operation 800 performed by the control system to coordinate retrieval of the seismic node deployment system from the water column. As with deployment, to begin the retrieval operation, the cable must be attached to a spool and threaded through the front, tension, node coupling devices and rear buffer systems, as indicated in the start configuration state 802.

Next, the control system determines whether the front and rear pinion pulleys are in the appropriate starting positions for node retrieval and removal, located forward and downward, respectively, as indicated in operation 804. If the front and rear pinion pulleys are not in place, the control system will actuate the motors that move the front and rear pinion pulleys into place on the rack.

Once the cable is in place in the deployment system and the front and rear pinion pulleys are in the proper starting position, the control system will actuate the motor on the spool to wind the cable at a constant speed, as indicated in operation 806. In conjunction, and in some cases simultaneously, the control system will actuate the motor of the driven pulley in the cable tensioner to place the appropriate tension on the cable within the system, as indicated in operation 806. After actuation of the spool and cable tensioner, the control system constantly monitors and adjusts the power to the spool motor and cable tensioner motor and the gear shift (gear change) of the transmission affecting the spool motor and cable tensioner motor in order to maintain proper tension on the cable and resist the constantly changing forces on the cable, e.g., the force of the moment of the cable mass as the spool rotates and takes more cable mass, and the force from the water column dragging over the varying cable length in the water column.

The control system also maintains a constant speed of the spool for retrieving the cable from the water column at the same constant speed, as indicated in operation 808. The control system may also coordinate the rotational speed of the driven pulley in the tensioner system to pull the cable through the tensioner system at the same speed as it is wound on the spool. As the cable is coiled, the control system also monitors the length of cable retrieved from the water column as indicated in operation 708 in order to identify a location for positioning a node within the node coupling apparatus in order to remove the node from the cable. Typically, the nodes will be located and attached at equal separation distances along the cable. However, the nodes may be attached to the cable at different separation distances as needed to meet any particular seismic recording requirements. In addition to or instead of monitoring the cable length, the control system may monitor the presence and location of the nodes only as they pass through the components of the deployment system on the aft deck.

As indicated in operation 812, the control system specifically determines when a node has traversed the post-buffering system and coupled the device to it. At this point, the front pinion pulley is moved rearward and the rear pinion pulley is simultaneously moved upward at approximately half the winding speed of the cable onto the spool, as indicated in operation 814. By moving the front and rear pinion pulleys in this manner to take up cable length on the rear end and pay out stored length on the front end, the cable section with the attached node at the node coupling arrangement is substantially stationary or moves at a significantly reduced speed relative to the node coupling arrangement during its traversal of the rack by the front and rear pinion pulleys.

By effectively stopping the movement of the cable through the node coupling device, the node can be easily disconnected from the cable during the time that the front and rear pinion pulleys are traversed the length of the lateral and vertical racks, respectively, as indicated by operation 816. Typically, this traversal time is on the order of a few seconds. This is sufficient time for: the node coupling apparatus grasps a node on a cable, compresses a spring clip, removes an expanded clip from around the cable, releases the spring clip on the node, and places the node for storage or maintenance activities. Once the front and rear pinion pulleys reach their rear and upper positions of the ends, respectively, the control system returns them to their starting positions to wait for the next node while the cable continues to be reeled in from the water column and stored on the spool at a constant speed.

Examples of the invention

Suitable system and apparatus embodiments include a seismic node deployment system comprising: a cable supplier configured to supply a cable; and one or more seismic nodes configured to be coupled to the cable at attachment locations for deployment to a water column. The node attachment system may be configured to drive a portion of the cable in a reciprocating motion, for example, between the cable supply and the water column, wherein the velocity of the cable is substantially reduced adjacent to the attachment location relative to the over-the-board velocity at which the cable is paid out to the water column to deploy the seismic node.

A seismic survey vessel may have a plurality of such seismic node deployment systems, each disposed in a generally parallel and longitudinal manner on the rear deck. A seismic array may include a plurality of seismic cables coupled to such a seismic node deployment system and thereby deployed to a water column.

Suitable method and process embodiments include: providing a cable; discharging the end of the cable to the water column; and driving a portion of the cable in a reciprocating motion relative to the paid out end. The velocity of the cable portion in reciprocation may be reduced relative to the overboard velocity of the payout cable, and one or more seismic nodes may be coupled or attached to the cable portion at the reduced velocity for deployment along the cable to the water column.

In any of the above examples and embodiments, during each cycle of reciprocation, the attachment speed may be reduced to substantially zero for a short period of time (e.g., from a fraction of a second to a few seconds, as appropriate), where the attachment speed of the cable is defined relative to the seismic node attachment/detachment equipment or the rear deck area. In some embodiments, the attachment speed may be reduced relative to the over board speed during each cycle of the reciprocating motion for up to at least five seconds. Similarly, the attachment speed may be reduced relative to the over-board speed or relative to the speed of the supply cable for at least 25% of the period of reciprocation. Alternatively, the cable supply speed may be controlled to adjust the tension in the cable portion to which the node is attached.

In any of the above examples and embodiments, the reciprocating cable portion may engage with at least one pulley member fixed to the reciprocating carriage, thereby driving the reciprocating movement of the cable portion. For example, the cable portion may make a single pass between two such pulley members secured at opposite ends to the reciprocating carriage, or make at least two passes between such pulley members secured to the reciprocating carriage. The cable portion may also be engaged with at least one stationary sheave member, such as a sheave attached to the rear deck clamp that is stationary relative to the reciprocating carriage.

Depending on the sheave configuration, the maximum reciprocation speed of the carriage may be about half or less of the over-board speed of paying out the cable and deploying the seismic node into the water. For example, the maximum reciprocation velocity may be 1/n or less of the overboard velocity at which the seismic node is deployed on the cable, where n is between two and eight, inclusive. Alternatively, n may be greater than eight.

The reciprocating motion may be oriented generally transverse to a cable path defined between providing the cable (e.g., at a winch or spool system) and paying out an end of the cable to a water column (e.g., at a sheave on a rear end of the rear deck). Alternatively, the reciprocating motion may be oriented substantially along a cable path similarly defined between providing the cable and paying out an end of the cable to the water column.

Multiple seismic nodes may also be coupled to different portions of the cable while discharging into the water column, for example, to deploy seismic streamers or node lines, with the nodes disposed in selected locations along the cable. The nodes may also be attached to different cables, for example, in order to deploy a multi-cable seismic array, with the nodes disposed in selected locations along each cable.

All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, front, rear, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the structures disclosed herein and do not create limitations, particularly as to the position, orientation, or use of such structures. Unless otherwise specified, connection references (e.g., attached, coupled, connected, and engaged) are to be construed broadly and may include intermediate members between a group of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other. The exemplary drawings are for illustrative purposes only and the dimensions, positions, order and relative dimensions reflected in the drawings attached hereto may vary.

While the disclosure has been made with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted to adapt the teachings to various technical problems, materials, and solutions while remaining within the spirit and scope of the invention. Therefore, it is intended that the invention not be limited to the particular examples disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (43)

1. A node deployment system comprising:

a cable supplier configured to provide a cable for attachment of one or more nodes configured for deployment along the cable to a water column;

a coupling device configured to drive the cable, wherein an attachment speed of the cable adjacent to the coupling device is reduced relative to a deployment speed of the cable to the water column for attachment of the one or more nodes.

2. The node deployment system of claim 1 wherein the coupling device further comprises a rear buffer system that alternately takes up cable length and releases stored cable length.

3. The node deployment system of claim 1, wherein the coupling device further comprises:

a front buffer system that alternately takes up cable length and releases stored cable length; and

a rear bumper system that combines the take-up and release performed by the front bumper system and alternately takes up cable length and releases stored cable length in reverse.

4. The node deployment system of claim 1 wherein the coupling device is configured to drive a portion of the cable in a reciprocating motion such that an attachment speed of the cable adjacent to the coupling device is periodically increased and decreased relative to the deployment speed of the cable to the water column.

5. The node deployment system of claim 2 wherein the coupling device is configured to drive a portion of the cable longitudinally in a reciprocating motion along a path of the cable defined between the cable supplier and the water column.

6. The node deployment system of claim 2 wherein the coupling device is configured to drive the portion of the cable in a reciprocating motion transverse to a path of the cable defined between the cable supplier and the water column.

7. The node deployment system of claim 1, wherein

The coupling device comprises at least one pulley fixed to the carriage; and

the cable is engaged with the carriage via the at least one pulley.

8. The node deployment system of claim 7, further comprising a mechanical drive configured to drive the carriage such that an attachment speed of a portion of the cable is periodically substantially stationary adjacent the coupling device for attachment of the one or more nodes.

9. The node deployment system of claim 8 wherein when the portion of the cable is substantially stationary, the velocity of the carriage is between 1/8 and 1/2, inclusive, of the velocity of the deployment of the cable to the deployment velocity of the water column.

10. The node deployment system of claim 7, wherein the speed of the carriage when the one or more nodes are attached is one half or less of the deployment speed of the cable to the water column, or wherein the speed of the carriage when the one or more nodes are attached is one quarter or less of the deployment speed of the cable to the water column.

11. The node deployment system of claim 1, wherein,

the coupling device includes a plurality of pulley members secured to a reciprocating carriage; and is

The cable is coupled to the reciprocating bracket by engagement with the plurality of pulley members.

12. The node deployment system of claim 11, wherein,

the cable makes only a single pass between the pulley members fixed to the carriage to attach the one or more nodes to the cable; or

At least some of the pulley members are fixed at opposite locations on the carriage and the cable makes at least two passes between the at least some pulley members.

13. The node deployment system of claim 11 further comprising at least one stationary pulley fixed relative to movement of the reciprocating carriage, wherein the cable is engaged between the reciprocating carriage and the at least one stationary pulley.

14. The node deployment system of claim 1, further comprising an obstacle or obstacle disposed along the cable, wherein the coupling device is configured to manage a buffer length of the cable to control or maintain a speed or tension at which the cable is provided by the cable supply or deployed to or retrieved from the water column while the obstacle or obstacle is disengaged.

15. A method of deploying a node on a cable, the method comprising:

discharging the end of the cable into the water column;

driving a portion of the cable into motion relative to the end paid out into the water column, wherein the speed of the portion is periodically reduced relative to the end of the cable paid out into the water column;

coupling a node to the portion as the speed decreases; and

deploying the node on the cable into the water column.

16. The method of claim 15, wherein

When the node is coupled to the portion of the cable, the portion of the cable is substantially stationary relative to the node; or

The portion of the cable is periodically substantially stationary relative to the node for between one tenth of a second and at least one second.

17. The method of claim 15, further comprising:

managing a buffer length of the cable to control or maintain a speed or tension at which the cable is provided or paid out to or retrieved from the water column; and

while controlling or maintaining the speed or tension, separating an obstacle or barrier from the cable.

18. The method of claim 15, wherein,

during each cycle of periodic movement of the end of the cable relative to the discharge to the water column, the speed of the portion of the cable is reduced for at least five seconds, or

The portion of the cable is reduced in speed for at least 25% of the period of reciprocation of the end of the cable relative to the column of water being discharged.

19. The method of claim 15, further comprising: engaging the portion of the cable with at least one pulley member secured to a reciprocating carriage, wherein periodic movement is driven thereby.

20. The method of claim 19, wherein,

said portion of said cable making only a single pass between such pulley members secured in each of two opposite positions on said reciprocating carriage; or

The portion of the cable makes at least two passes between such pulley members secured in each of two opposite positions on the reciprocating carriage.

21. The method of claim 15, wherein a maximum reciprocation speed of the carriage is 1/n or less of a cable speed at which the node is deployed, where n is between two and eight, inclusive.

22. The method of claim 15, further comprising: controlling tension in the cable with a sheave system disposed between the water column and the portion of the cable in reciprocation, wherein the reciprocation is oriented substantially transverse to or longitudinally along a path defined between providing the cable and paying out an end of the cable to the water column.

23. A node deployment system comprising:

a cable supplier configured to supply a cable;

one or more nodes configured for coupling to the cable at an attachment location for deployment to a water column;

a node coupling device configured to attach and detach the node to and from the cable;

a node attachment system configured to drive a first portion of the cable to move periodically between the cable supply and the node coupling device and to drive a second portion of the cable to move periodically between the node coupling device and the water column, wherein a first velocity of a third portion of the cable is substantially reduced adjacent to the attachment location relative to a second velocity of the cable when the cable is deployed to the water column with the attached node or when the cable is retrieved from the water column.

24. The node deployment system of claim 23 wherein the first velocity is periodically substantially zero such that the third portion of the cable does not move relative to the attachment location.

25. The node deployment system of claim 23, wherein the node attachment system further comprises a rear buffer system that alternately takes up cable length and releases stored cable length.

26. The node deployment system of claim 23, wherein the node attachment system further comprises:

a front buffer system that alternately takes up cable length and releases stored cable length; and

a rear bumper system that combines the take-up and release performed by the front bumper system and alternately takes up cable length and releases stored cable length in reverse such that the periodic motion is reciprocal.

27. The node deployment system of claim 26, wherein the front buffer system further comprises:

a front rack;

a front pinion pulley movably connected to the front rack and around which the cable passes; and

a motor driving the front pinion pulley back and forth along the front rack to take up cable length and release stored cable length.

28. The node deployment system of claim 26, wherein the back buffer system further comprises:

a rear rack;

a rear pinion pulley movably connected to the rear rack and around which the cable passes; and

a motor driving the rear pinion pulley back and forth along the rear rack to take up cable length and release stored cable length.

29. The node deployment system of claim 26, wherein the back buffer system further comprises:

a first stationary base pulley positioned at an end of the rear rack and around which the cable passes; and

a second stationary base pulley spaced apart from the first base pulley, positioned at an end of the rear rack, and around which the cable passes; and

wherein the rear pinion pulley travels between the first and second stationary base pulleys.

30. The node deployment system of claim 26 wherein the rear rack is positioned in a vertical orientation.

31. The node deployment system of claim 26, further comprising a tension drive pulley between the front and rear bumper systems through which the cable passes, wherein the tension drive pulley advances the cable toward the water column and controls tension in the cable between the node attachment system and the water column.

32. The node deployment system of claim 23 wherein said cable supplier is a motor-driven spool.

33. The node deployment system of claim 23, wherein the second speed of the cable is a speed of up to 5 m/s.

34. The node deployment system of claim 23, further comprising a control system that coordinates reciprocation of the first portion of the cable with reciprocation of the second portion of the cable.

35. A vessel having node deployment systems according to claim 23, each node deployment system being provided on a rear deck of the vessel.

36. A method of deploying a node on a cable, the method comprising:

providing a cable from a cable source;

discharging the end of the cable to the water column at the over board speed;

driving a first portion of the cable between the cable source and a nodal attachment location in a periodic motion;

driving a second portion of the cable in a periodic motion between the node attachment location and the water column, wherein a third portion of the cable positioned at the node attachment location travels at a reduced attachment velocity relative to the over board velocity;

coupling a node to the third portion of the cable at the attachment speed; and

deploying the third portion of the cable and the attached node together into the water column at the over board speed.

37. The method of claim 36, wherein the periodic motion is reciprocating and the attachment speed is reduced to substantially zero relative to the node when the node is coupled to the third portion of the cable.

38. The method of claim 36, further comprising reducing the speed of the third portion to the attachment speed for at least five seconds during each cycle of the periodic motion.

39. The method of claim 36, wherein the overboard velocity is up to 5m/s, or wherein the overboard velocity is 5m/s or greater.

40. The method of claim 36, wherein the speed of the periodic motion of the first portion of the cable is up to half of the over board speed.

41. The method of claim 36, wherein the speed of the periodic motion of the second portion of the cable is up to half of the over board speed.

42. The method of claim 36, further comprising controlling tension in the cable between the water column and the first portion of the cable in periodic motion.

43. A method of node retrieval, the method comprising:

pulling the deployed cable with the attached node out of the water column at the boarding speed;

driving a first portion of the cable between a cable spool and a node removal location in a periodic reciprocating motion;

driving a second portion of the cable between the node removal location and the water column in a cyclic reciprocating motion, wherein a third portion of the cable positioned at the node attachment location travels at a reduced separation speed relative to the boarding speed;

separating a node from the third portion of the cable at the separation speed; and

storing the cable around the cable spool at a winding speed equal to the boarding speed.